Magnetic only Motor Circuit Protection Breaker

[Venkatec2018]

Hello all,

Can someone please help me with my below questions ?

I have a Square D I-Line distribution panel with six breakers. There are 6 breakers in this I-Line distribution panel. Each breaker feeds one motor starter circuit. The connection is as shown below.

I-Line panel Feeder Breaker -> Fused Disconnect -> Starter Panel (with contactor & overload relay) -> Motor.

The distance between I-Line panel feeder breaker to starter panel is 30 to 40 feet. The starter panel has overload inside for thermal protection. The starter panel also has fused disconnect.

Question 1

Is it ok to use Motor Circuit Protector breaker with only magnetic trip in the I-Line panel ?

Question 2

Does the I-Line panel feeder breaker need to provide both thermal and magnetic protection ?

Question 3

Which section of NEC is applicable to this scenario ?

Question 4

Ideally when overload condition happens, the overload relay inside my starter panel will trip protecting the breaker and cable. In addition to this, should the I-Line feeder breaker provide thermal protection for cable running between I-Line panel and starter panel ?

Thanks & Regards,

Venkat

 

[augie47]

1 No

The rest of your questions are answered by 430.52(C)(3)
ITs can only be used as part of a listed combination motor controller.

 

[Jraef]

1 No

The rest of your questions are answered by 430.52(C)(3)
ITs can only be used as part of a listed combination motor controller.

+1
There is no NEC acceptable use of “MCP” (Magnetic-Only) circuit breakers outside of a listed factory assembled and tested combo starter. The only reason they are sold is (ostensibly) as direct exact replacement parts.

 

[kwired]

+1
There is no NEC acceptable use of “MCP” (Magnetic-Only) circuit breakers outside of a listed factory assembled and tested combo starter. The only reason they are sold is (ostensibly) as direct exact replacement parts.

Which also probably means you wouldn't even find one with jaws for plugging onto I line bus, I would think. Usually would be a unit mounted in a MCC bucket and would have lugs on both ends of the breaker.